2002 volvo s60 Do I have a bad engine computer?

[turtlehead]

Okay guys, here is my problem. I bought a 2002 S60 non-turbo that had lost its timing belt and needed valve work. In other words, it was not a running car when I bought it. So I replaced the head and set the timing- it has vvt on the intake. Now the darned thing starts but it will only run for about thirty seconds, and then die. I checked the error codes, and got P0339 and P0341, which is crankshaft position sensor intermittent, and camshaft position sensor. So I cleared the codes and replaced both sensors.

The weird thing is I noticed that if I unplug the cam position sensor, the engine doesn't die any more but its obviously not running right. I've driven it with the cam sensor unplugged but it isn't a smooth ride. Nothing I've tried works in getting rid of the two error codes.

I thought maybe I had a short in the wiring, so I bought a wiring harness from a local u-pull-it and replaced the harness between the sensors and the engine computer, but I still get the same two codes. Since I've eliminated the sensors, and the wiring as possible culprits, my thinking now is that I must have a bad computer.

I bought a used computer from the junkyard and got a quote from Lucky at Ard for cloning my existing computer, but he suggested that I check the ground straps. I removed the ground strap that runs from the transmission to the frame, cleaned it, and put it back. I also installed a new strap from the cam cover to the frame, but I'm still getting the same codes. So far as I can tell I've grounded the hell out of it, and I'm still getting the same two codes. Lucky will clone my computer for $175 if I provide him a good used one.

Am I missing something here? Is there anything else I should check before I pull the trigger on replacing the engine computer?

[jimmy57]

Don't replace the computer, that is very unlikely to be it if it runs at all.

Have you rechecked timing? remove the cam sensor and exh. cam cover plug and turn engine until crank mark is aligned and see if the cam lock tool falls in place.

Does the timing reluctor on the end of intake cam have 5 varying tooth profiles? (turbo engines have 4 teeth, 2 wide, 2 narrow).
That it runs with cam sensor unplugged tells me the computer is fine but the cam to crank synchronization can't be completed by the ECM.
With cam sensor missing it will run in a limp home with less ignition advance so low power is normal then.

[turtlehead]

Thanks, Jimmy57. Your comments make logical sense to me. The timing reluctor (which is on the intake cam), looks just like you described, so I will double check the timing now. I removed the intake vvt hub to replace the seal, so it is possible that what I have is actually a timing issue rather than the sensors, wiring or computer. This is the first time I've worked on a vvt engine. I may not have set up the vvt correctly when I reinstalled the hub.

I will post again after I've checked the timing.

[turtlehead]

I checked the timing, by doing the following:

I aligned the crankshaft by lining up the two marks on it so that the mark on the engine case is in the valley. I removed the exhaust cam plug and the intake cam sensor and also the reluctor. Then I looked at the cam gears, and the marks on them looked to be in the correct position. I installed the cam lock tool, and the top half and bottom half were parallel, almost touching. Thinking that maybe that one or two millimeter's difference might be causing the problem, I reset the timing by loosening the vvt center bolts and adjusting the intake hub clockwise just a hair so the cam lock tools touched. I can tell that it is already at its clockwise limit position with the timing belt installed.

I put everything back together, installed reluctor and cam sensor, plugged it all in, and started the engine. It starts immediately, runs for about thirty seconds, then dies. It will start and run like this every time I turn the key. I also am getting the same two codes- intermittent crankshaft sensor, and bad cam sensor.

I did all this between six am and about 7:30 this morning, I've got to go to work now, but I will re-do the timing once more tomorrow morning even though I am not sure any more that it is in fact the problem. I am about to get the local volvo mechanic involved, grrr. Somebody stop me before I do that with some good advice please?

[turtlehead]

I followed Jimmy57's excellent instructions on setting the timing on my 2002 S60, but no change in symptoms. Here is what I get: With the cam sensor plugged in, the engine starts immediately, runs for about thirty seconds, then dies. Fuel pressure is around 50 PSI, and does not change when the engine stalls. If I unplug the cam sensor, the engine takes a few seconds to start but when it does, it runs continuously, albeit not smoothly and if I try to drive it I get a random misfire code.

I have confirmed that the timing belt is in the correct position, I think- I manually spun the engine two times around clockwise, then lined up the crankshaft mark, and looked to see if the cam lock tool falls into place, and it does. I'm at my wit's end on this thing. Is there anything else besides a faulty computer?

I have vida on the way, hopefully it will arrive in the next few days and maybe that will tell me what I'm doing wrong here. Could it be an immobilizer issue?

[precopster]

If you really must replace the computer just wait for the Dice and contAct doublebug. Henry can do this for you over the internet and save you some dollars and wasted time for shipping.

Go and get an intake cam with VVT hub attached and push a new seal on from the rear. That is iny opinion where you went wrong.

[turtlehead]

I am very reluctant to conclude that it is the computer. The seller told me that the car was running and the timing belt broke. Once I opened it, the valves were bent so everything that I saw matched up with what the seller told me. There are some other problems with it (clogged PCV, for example) but it looks like the car ran and drove, and so far as I know you don't get a broken timing belt and bent valves any other way.

I actually have a spare intake cam with the hub attached, so I will swap it out and see what happens. It never even occurred to me that I could install the cam seal from the opposite end!

I will post again once I've swapped it out. If that solves my problem, then clearly it isn't the ECU, and we can all conclude that the real problem is just a bad gene pool.

[doublebug]

First I would try to just reload fw. Sometimes it gets corrupted so it may stall randomly.

[turtlehead]

I replaced the intake cam with the spare, and I still get the same result.

During the process, however, I noticed that the wire that operates the vvt solenoid is actually loose- the plastic mechanism that holds the wire in place was broken, so I had a moment of "aha" where I thought that maybe I had discovered the trouble. I used a ziptie to secure the loose wire, and I'm confident now that the vvt solenoid is getting power. Maybe the loose wire might help explain the random misfire codes I've been getting, but with the spare cam installed, the engine starts, runs for about thirty seconds, and then dies. It runs for as long as I want if I disconnect the cam sensor.

So now I'm back to my original question- now that I've tried everything else, is my computer bad?

I have a spare that I picked up from the u-pull-it. I will pm doublebug and see what he thinks.

I will also post back here so y'all will know what the result was.

[precopster]

If you had Vida/Dice you could view ECM Parameters and view camshaft control desired and actual values with engine running.

Lots of Denso cars like yours are apparently dropping output to VVT solenoid however yours is more serious than that.